The decision follows weeks of unrest in the southern region of Arequipa and a presidential address to the country on Friday urging the miner to do more to build support for the project.

"In the spirit of recovering the climate of peaceful coexistence that the country needs, we ask for the time and terms needed to socialize the project and clear up existing doubts in the next 60 days," Chief Executive Oscar Gonzales said in a statement.

Tia Maria has faced delays since 2011, when similar rallies by farmers who say the mine will pollute the surrounding agricultural valley also left three dead.

The company has said it will use the highest standards and made several revisions to its environmental plan, which was approved last year.

A construction permit was pending when renewed protests broke out March 23.

President Ollanta Humala said Southern Copper might sue Peru if it canceled Tia Maria and urged the miner to explain the benefits of the project to reluctant locals.

"I insist the company manifest its will and execute concrete actions to create a foundation of understanding," Humala said.

Earlier on Friday, police announced the arrest of a leading opponent of the 120,000-tonnes-per-year copper project amid allegations he tried to extort the company for $1.5 million in exchange for calling off rallies.

Peru said this week that it was probing whether Southern Copper knew about but failed to report the alleged crime to authorities and halted talks with the miner.

Two protesters and one policeman have been killed in almost daily protests over the past seven weeks. Authorities said that two people in need of urgent medical care also died this week on a highway blocked by protesters.

TV images from Thursday showed police firing tear gas at fleeing protesters and a group of men beating a policeman.